Promise of dual carbon batteries with graphene-like graphite as both electrodes

Abstract

Graphene-like graphite (GLG) exhibits a higher capacity for intercalation/deintercalation of lithium ions and anions compared to graphite, making it a promising candidate for both electrodes for dual carbon batteries, also known as dual-ion batteries (DIBs). In this study, we constructed DIB full cells with GLG electrodes to address specific issues related to the full cell while optimizing the cell configuration and charge-discharge conditions to improve its performance. With 3 mol dm−3 LiPF6/ethyl methyl carbonate (EMC) electrolyte solution, the reversible capacity was very small, suggesting that this was due to a cross-talk reaction where decomposition products generated at the cathode migrated to the anode and were reductively decomposed. Conversely, the use of 3 mol dm−3 lithium bis(fluorosulfonyl)amide (LiFSA)/EMC suppressed the cross-talk reaction, resulting in improved charge-discharge performance. In addition, the pre-cycling of the anode to form solid electrolyte interphase significantly suppressed the cross-talk reaction to greatly increase the reversible capacity. Consequently, we achieved a relatively high capacity of 66 mAh g−1 for the GLG cathode, even with a low cutoff voltage at 4.6 V, surpassing the capacity of a dual graphite battery under the same conditions. This outcome clearly demonstrates the promise of GLG as active materials for DIBs.